Printing plate mold



June 16, 1931. J. scHMuTz PRINTING PLATE MOLD Filed July 51,

2 Sheets-Sheet l J. scHMUTz 1,810,088

PRINTING PLATE MOLD Filed July 3l, 1929 2 Sheets-Sheet 2 OOOOO June 16, 1931.

Patented June 16, 1931 UNITED STATES PATENT OFFICE PRINTING PLATE MOLD Application led July 31, 1929. Serial No. 382,554.

and pressure, and which is not subject to appreciable contraction and expansion during the course of such molding process.

Another important object of this invention is the provision of a reinforced composition mold of this character substantially immune to contraction and expansion, formed with a perforated metal backing and perforated metallic border on the top or face thereof' for molding resilient printing plates and capable of producing type shoulders of suflicient height for coarse fabric bag printing such as burlap, cotton, corrugated paper boxes, galvanized sheet iron, sheet packing, etc., the type shoulders presenting sharp contours for effecting accurate register where a plurality of plates for color printing are employed.

Vith these and other objects in View, which will become apparent as the description proceeds, the invention resides in the construction, combination and arrangement of parts, hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which like characters of reference indicate like parts throughout the several ligures, of which Fig. 1 is a top plan view of the negative or pattern plate, the chase, and perforated border pieces in position prior to the introduction of the moldable material;

Fig. 2 is a transverse cross section on lines 2-2 of Fig. 1;

F ig. 3 is a similar view to Fig. 2 after the moldable material has been added;

Fig. 4 is a similar view to Fig. 3 after the metal backing has been applied;

Fig. 5 is a plan view of my improved completed mold; and

Fig. 6 is a similar view of a like mold showing a variation in the type forming depressions.

lVhile Iam aware that paper face, metal face and composition molds have been employed for the production of printing plates, there have been certain disadvantages incident to all such forms. The disadvantages of the paper face, including at times adherence thereto of the rubber plate being simultaneously molded and vulcanized; the deficiencies of the metal plate including not admitting of suliiciently sharp contour of the type face of the shoulder portions, when such portions are necessary to be of sufHcient height for coarse fabric printing such as burlap, etc., and the softening of the metal on account of the vulcanizing heat, causing a spreading and changing of the mold shape as a result of the heat and pressure of the rubber or composition, the disadvantages of composition molds among others being their tendency to expand and contract and crack, thereby allowing the rubber compound to flow therein when simultaneously subjected to eXtreme heat and pressure incident to the molding and vulcanization of the plate, and not only consequent deficiency in the production of a plurality of plates necessary for color printing, where the several colors must accurately register, but causing subsequent disintegration of the mold, and it was to overcome the deficiencies of all of such types of molds and to provide a composition mold where the moldable subst ance would not adhere thereto during course of molding, would not be subject to appreciable expansion and contraction during the application of extreme heat and pressure to the moldable substance during course of molding, susceptible of producing type shoulders of suicient height for coarse fabric printing,

said shoulders presenting such sharp contours as to effect accurate register of various colors where a plurality of plates are employed in color printing, that Il designed the mold and process forming the subject matter of this invention.

In the illustrated embodiment characterizing this invention there is shown a mold A, positive or attern plate B and frame or chase C, andp 1n carrying out the process of my invention, the pattern plate B bearing a suitable design 1 is placed on the platen of the vulcanizing press (not shown) and then around the pattern is placed the chase C, in the present instance comprising a steel frame of a thickness governed by the thickness of the mold to be produced, then set in the four sides of the plate are metal perforated strips 2 of any desired metal. Though I have preferably shown these strips as perforated, their embedded surfaces may be knurled, plain, grooved, etc., or they may be formed of a plurality of strips such as wire rods, very narrow flat pieces or in the form of a screen. The chase isthen filled with a quantity of moldable compound 3, and while this compound may comprise a variety of constituents depending upon the requirements, in the present instance, it is a compound in the nature of a resinoid condensation product suitable for molding purposes such for example, as that commerclally termed Durez, which is a well known resinoid or phenolic product, and which when subjected to a predetermined de ree of heat and ressure assumes a firm an substantiall in usible form. A rubber compound, bakelite, or the like, may also be used with good results.

A metal backing 4 corresponding to the plane area of the mold, and constituting a backing therefor is placed or superimposed over the moldable compound and the mass simultaneously subjected to preferably a thousand pounds hydraulic pressure and 8O pounds steam pressure per square inch from one-half hour to an hour, depending upon the area and thickness of the mold, whereby the moldable material is vulcanized and forced through perforations 5 and through the perforations or around strips 2, or into knurled, grooved or other surface depressions, said perforations, depressions, etc., constituting keyways by means of which the metal backing and the strips are firmly locked to the composition body of the mold. The metal back 4 being coextensive with and vulcanized to the plane area of the mold, and the metal face strips vulcanized and locked tothe face of the mold surrounding its edges, combine with the mold body when thus united to form such an integral and homogeneous structure as to be substantially immune from expansion and contraction and to such an extent as not to interfere with the proper register of printing plates produced by such mold when used for multicolor printing.

Followin the vulcanization process as above described the mold is removed from the lphase and is then in the form designated as The mold A formed as above described is now ready to be lled with the moldable compound from which the printing plate is ormed, and will not appreciab y expand, contract or become otherwise distorted even under extreme heat and pressure applied to the plate forming the substance, and it is ap arent that a plate manufactured from this mo d, having type shoulders of the height of the type shoulders 6 of plate B and oorresponding to the depression 7 of the mold is sufficient to effect a clear non-blurred imprint on coarse fabrics and the sharp line contour of the type face of the printing plate corresponding to the face 8 of plate B effects an accurate register when a plurality of plates are required in printing multicolor Work, and which has been incapable of accomplishment from the types of composition molds heretofore in use.

Where multicolor printing is desired a complemental mold formed wlth corresponding indicia but varying in the type forming depressions in the mold is necessary su`ch as illustrated in Fig. 3, and which mold is identical to that above described in the formation of the letters or design.

Further description with respect to the complemental mold is thought unnecessary, and in fact, reference to this mold is sim l made for the purpose of showing a mu t1- plicity of plates produced from molds of this type are adapted to effect perfect register when it is desired to rint in two or more colors, and which, as a ove stated, has been impossible with composition molds heretofore in use.

One of the reasons why composition molds have not been successfully applied in the printing art is due to the fact, as above stated, that when subjected to extreme heat and pressure during the plate molding process they would break down and become distorted and consequently be incapableof successful use, and it was to overcome such deliciencies that I produced my improved mold, having a plurality of portions of the mold body extending through and vulcanized to a metallic backing co-extensive with the surface area of the mold and with its face simultaneousl keyed and vulcanized to a metallic border frame, thereby resenting such a homogeneous integrally ormed unitary structure as to be capable of maintaining the mold in its original form when subjected to extreme heat and pressure dluring the printing plate molding process.

Although in practice I have found the form of my invention illustrated in the accompanying drawings and referred to in the above description as the preferred embodimentis the most eflicient and practical; vet realizing that conditions concurrent with the adoption of my device will necessarily vary, I desire to emphasize that various minor y,changes in details of construction, proportion and arrangement of parts, may be resorted to within the scope. of the appended claims without departing from or sacrificing any of the principles of this invention.

Ha ving thus described my invention, what I desire protected by Letters Patent is as set forth in the following claims:

1. A method consisting in the step of keying a plastic compound to a metallic backing and its opposite surface to a metallic border by the application of heat and pressure.

Q. A method consisting in silnultaneously keying and vuleanizing a metallic backing to one surface of a plastic compound and a metallic border to the opposite surface by the application of heat and pressure.

3. A method consisting in placing a perforated metallic backing on oneI surface of a plastic compound and a metallic border frame on the opposite surface and simultaneously forcing portions of the plastic compound into the perforations of said back and c frame by the application of heat and presface area and applying a metallic perforated border frame adjacent the edge-s of its opposite surface andforcing into said perforations and vulcanizing therein portions of the plastic compound by the application of heat and pressure.

5. A method consisting of applying a positive design bearing plate and a metallic perforated border frame to one surface of a moldable plastic compound, and a perforated metallic backing to the opposite surface of the compound, simultaneously forcing portions of the compound into the depressions of the design bearing plate, into the perforations of the frame and backing and vulcanizing the same therein by the simultaneous application of heat and pressure.

6. A method consisting in simultaneously forming type forming depressions and nontype forming elevations from a positive type plate in one surface of a moldable plastic compound and keying a perforated metallic border to said surface and keying a perforated metallic back eo-extensive with its surface area to the opposite surface by forcing and vulcanizing a plurality of portions of the compound into the perforations of the frame and back by the simultaneous application of heat and pressure.

7. A method of producing a printing plate mold consisting in placing a moldable substance on a design bearing plate and on a metallic border surrounding Said plate, placing a metallic backing over the moldable substance and subjecting the assembly to heat and pressure to form design forming depressions and non-design forming elevations in such substance and firmly unite said lnetallic border, moldable substance and back into a homogeneous structure.

8. A method of producing a printing plate mold consisting in placing a moldable substance on a positive type bearing plate and on a metallic border surrounding said plate, and then placing a perforated metallic backing over the moldable substance co-extensive with the surface area thereof, and subjecting the assembly to heat and pressure to vulcanize said substance and form type forming depressions and non-type forming elevations therein and to simultaneously lill the perforations with said moldable substance to'firmly unite said components into a homogeneous sembly to heat and pressure in sufficient degree to form type-forming depression and non-type-forming elevations and to force said substance into the perforations of said border to firmly lock it to one surface of the substance, at the same time forcing the substance into the perforations of said back to firmly lock it to the opposite surface of the substance to unite said border, moldable substance and back into an integral structure.

10. A method of producing a printing plate mold by placing a body portion of moldable substance on a design bearing plate and on a metallic border surrounding said plate formed With a plurality of keyways, and placing a metallic backing likewise formed with a plurality of keyways over the moldable substanee co-extensive With its surface area, simultaneously subjecting the assembly to suflicient heat and pressure to simultaneously vulcanize the moldable substance and force it into the respective keyways of the frame and backing to unite and lock the border, mold body, and metallic back into a homogeneous structure.

11. A printing plate mold comprising a composition body portion formed Wit-h type forming depressions and non-type-forming elevations, a metallic frame co-extensive With the face edges and a metallic backing member so-extensive with the surface area of the body portion.

12. A printing plate mold comprising a composition body portion formed with design forming depressions and non-designforming elevations, a perforated metallic frame co-extensive with the edges and a perforated metallic backing co-extensive with the surface area.

6 13. A printin plate mold comprising a composition bo y portion formed with design-forming depressions and non-designforming elevations, a perforated metallic frame co-extensive with its face edges and lo having portions of the composition body enl gaging said erforations, and a perforated metallic bac 'ng having portions of said body engagin its perforations.

This s eci cation signed this 28th day of May, A. 1929.

l JULIUS SCHMUTZ. 

